Hi @explocarto, thanks for your answer.
Indeed, moreover the "loop" is the entire "data expression".
In order to obtain the same result with an expression in the "advanced formating" section, I would need to suceed in one of the following :
Bypass the unavailability of the "Filter" command in the expression editor
Manage to create a second reference (because it allow to filter) and use them in my expression
Thanks!
Frank